Trommel Multi screen

[rwells]

Do they make a multi screen trommel? Like 2 or 3 tubes inside each other that has a separate output for each size classified. I was thinking you could feed each of those outputs to sluice boxes especially set up for that size.

Just thinkin
Rick

[CalGoldDredger]

You could have more than one size screen in the same barrel with seperate sluices for each.
I would think you would have the bigger classification set up first in the barrel then the finer with a good gap between and plenty of wash.
You could also run an over/under sluice to classify even more if need be.

[Geo-George]

I don't know of any commercial units, but I'm thinkin' just like you.
I'm gonna work on one this winter. Been thinkin' 'bout some dif designs for a couple of years.
I've pretty much settled on a particular design.
Two barrel screens. One at 1/2" and one at 1/8".
Larger than 1/2", goes to tailings pile. Go over this with a detector.
1/8" and larger goes one way, smaller than 1/8" goes another.
Two "Long Toms", side by each, and I have plenty of water avail.
The second "Tom", 1/8" plus, is a security measure.
And a partner.
Keeps me from talkin' to myself.
It'll either work or it won't.

[Geo-George]

P.S.
The 1/2" barrel goes inside the 1/8" barrel.

[WildernessAU]

Hehe, I like your "Tom" partner comment George.
As for screen sizes that would probably have be determined by the dirt your digging and what kind of gold is in it. I don't think I would feel comfortable sending all 1/2 plus to the tailings pile. It seems like too much screen surface area where 1/2" and smaller stones....or nuggets could get chucked out.
D

[Joe S (AK)]

Geo,

In a single drum setup shouldn't the slurry go over the smallest mesh screening first (with a 90 deg to the side sluice) and then the second, larger, screening going 90 deg to one side or the other. Then the washed oversize should discharge from the bottom end of the drum?

If the larger screening is first, an entire second screening has to be made of that slurry to get the smallest undersize. That's a whole lot more work (with more things to go wrong) than allowing the rotating drum to do both cuts one after the other with a space between.

Joe

[Hoser John]

Process all screened oversize materials or you will be sorry. The 1/2 million $$$ Chicken creek nugget that was found whilst dozing a disguard pile into the creek is a prime example. John

[rwells]

Lots of good ideas here. I am going to collect all the thoughts and put them togather. Heard somewhere about incoorporating a rock scrubber of some kind in the first stage. Kinda like a potatoe scrubber or brushes in a car wash to clean the loose material off the rocks. Thought of a grizzley of some kind where the machine is fed to screen out anything above 1". Feed all that in to the center tube that has 1/2" holes. (Can sluice boxes handle 1/2 material if the riffles and water flow is right?). The next screen was going to be 1/4". Output of this will be 1/4 to 1/2". Run this to a sluice. Next screen is 1/8". Out of this screen tube comes 1/8 to 1/4. That goes to another sluice. What falls through the last screen is 1/8 minus down to dust. Run this to a sluice also. Well I'm starting to ramble. I need to quit and make some drawings. Later everyone.

Rick

[Geo-George]

Geo,

In a single drum setup shouldn't the slurry go over the smallest mesh screening first (with a 90 deg to the side sluice) and then the second, larger, screening going 90 deg to one side or the other. Then the washed oversize should discharge from the bottom end of the drum?
If the larger screening is first, an entire second screening has to be made of that slurry to get the smallest undersize. That's a whole lot more work (with more things to go wrong) than allowing the rotating drum to do both cuts one after the other with a space between.

Joe

Take note, there is one barrell with 1/8" screen on the outside, with a 1/2" barrell screen inside. The material is fed into the center barrell screen, 1/2" mesh. Anything over 1/2" travels out the end of the trommel. Material under 1/2 falls to the inside of the 1/8" barrell screen. The outer barrell screen carries everything between 1/2 and 1/8 out to one sluice, the finer material drops to the bottom and the other sluice. You want to screen out the larger material first and graduate to finer and finer. Your final screening is to classify out your finest material.

[Geo-George]

Process all screened oversize materials or you will be sorry. The 1/2 million $$$ Chicken creek nugget that was found whilst dozing a disguard pile into the creek is a prime example. John

John,
Two words,.....
Metal detector.

That's the Wife's job.